President Obama said the agreement with automakers on a 54.5 mile-per-gallon national average fuel economy standard by 2025 is the “single most important step” to cut U.S. dependence on foreign oil. Under the new standard the average motorist can fill up every two weeks, instead of weekly. Automakers must take major steps to get buyers into smaller vehicles, cut fuel use with turbochargers and hybrids, slash vehicle weight and look at other ways to build more aerodynamic cars.